Coupler

ABSTRACT

A coupler having a tubular body ( 6 ) which is arranged to receive a tubular element for transporting fluid and including a pipe end, and which is provided with elements ( 11 ) for snap-fastening the tubular element, the coupler including a bushing ( 15 ) provided on the inside with elements ( 23, 25 ) for retaining the pipe end, which elements are selectively activatable and deactivatable, wherein the bushing is mounted in the tubular body to be movable axially between a position for activating the retaining elements and a position for deactivating the retaining elements, and wherein the bushing is provided with snap-fastening elements complementary to those of the body for co-operating therewith in the activation position.

The present invention relates to a coupler for coupling together twofluid transport elements such as a pipe and a fluid receiver elementsuch as a tank or a fluid transmitter element such as a pump.

BACKGROUND OF THE INVENTION

So-called “instant” or “quick” connection couplers are known thatcomprise a tubular body arranged to receive a pipe end and providedinternally with means for retaining said pipe end. These means aregenerally constituted by a deformable washer whose inside circumferenceis subdivided into a plurality of teeth or claws which project into thetubular body. When the pipe end is inserted into the tubular body, thepipe end lifts the teeth so that their free ends come to rest againstthe outside surface of the pipe end. When pressure is raised in thecircuit in which the coupler is installed, the pipe end moves back alittle prior to the teeth coming to bite into the outside surface of thepipe end and serving to retain it. During insertion of the pipe end, theteeth which rub against the outside surface of the pipe end run the riskof scratching it.

Unfortunately, the coupling is generally sealed by means of an O-ringthat fits tightly around the pipe end, such that scratches run the riskof constituting leakage zones or of damaging the sealing ring to such anextent that it can no longer perform its function. It would be possibleto increase the flexibility of the washer in order to reduce the forceexerted on the outside surface of the pipe end by the teeth. Howeverthat would also reduce the strength of retention and would increase thedistance through which the pipe end moves backwards when pressure isapplied to the circuit. Unfortunately, such backward movement produces azone in which fluid is retained, which zone must be kept as small aspossible, in particular in circuits that convey a liquid that isperishable.

Quick-connection couplers are also known comprising a tubular bodyhaving a latch mounted to move thereon radially between a lockingposition in which the latch possesses a portion projecting into thetubular body, and an unlocking position in which said portion isretracted from the tubular body. The risks of the pipe end beingscratched or moving backwards are then small. However, it is necessaryto provide a setback either directly in the pipe end or in an endpiecemounted on the pipe end in order to co-operate with the latch of thecoupler.

OBJECTS AND SUMMARY OF THE INVENTION

An object of the invention is to propose a coupler that combines insimple manner the advantages of the above-mentioned prior art couplers.

In order to achieve this object, the present invention provides acoupler comprising a tubular body which is arranged to receive a tubularelement for transporting fluid and including a pipe end, and which isprovided with means for snap-fastening the tubular element, the couplercomprising a bushing provided on the inside with means for retaining thepipe end, which means are selectively activatable and deactivatable, thebushing being mounted in the tubular body to be movable axially betweena position for activating the retaining means and a position fordeactivating the retaining means, and the bushing being provided withsnap-fastening means complementary to those of the body for co-operatingtherewith in the activation position.

Thus, the bushing serves as an interface between the snap-fasteningmeans of the tubular body and the pipe end, and serves to retain thepipe end when it is in the activation position while insertion orremoval of the pipe end is left free when the bushing is in itsdeactivation position.

Preferably, the bushing is provided internally with abutment meansagainst insertion of the pipe end into the bushing, and the activationposition of the bushing is downstream from the deactivation positionrelative to the direction in which the pipe end is inserted into thecoupler.

Thus, when the pipe end is inserted into the tubular body, the bushingis entrained from its deactivation position to its activation position.The coupler thus constitutes a quick coupler.

In which case, advantageously, the bushing possesses a downstream endprovided with an elastically-deformable annular gasket having aninternal annular shoulder forming the abutment against insertion of thepipe end.

Under such circumstances, the annular sealing ring serves not only toperform its conventional sealing function, but also to perform anabutment function against further penetration of the pipe end into thebushing, and a function of compensating for the pipe end moving backwhen the circuit in which the coupler is installed is put underpressure. This makes it possible to limit the formation offluid-retaining zones.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention appear on readingthe following description of particular, non-limiting embodiments of theinvention.

Reference is made to the accompanying figures, in which:

FIG. 1 is an exploded longitudinal section view of a cartridge-typecoupler in accordance with the invention;

FIG. 2 is an elevation view of the tubular body of said coupler;

FIGS. 3 to 6 are longitudinal section views of this cartridge-typecoupler installed in a member of a fluid transport circuit, showing thevarious stages of inserting a pipe end;

FIG. 7 is a view analogous to FIG. 6 showing a variant embodiment of thecoupler; and

FIG. 8 is a view analogous to FIG. 3 showing a union-type coupler inaccordance with the invention.

MORE DETAILED DESCRIPTION

With reference to FIGS. 1 to 7, the coupler in accordance with theinvention is for coupling a pipe end 1 to the internal channel 2 of amember 3, which channel opens to the outside of the member 3 via acountersunk chamber 4 presenting a diameter greater than the diameter ofthe internal channel 2 and connected thereto via a tapering surface 5.

The coupler comprises a generally tubular body referenced 6 made ofthermoplastic material. The tubular body 6 possesses one end portion 7for insertion into the chamber 4 of the member 3 and an opposite endportion 8 for projecting from the member 3.

The end portion 7 is provided with means for anchoring it in the chamber4. In this example, these means are implemented in the form of a metalcramping washer 9 partially embedded in the tubular body so that theouter periphery of the cramping washer 9 projects radially outwards fromthe end portion 7.

The end portion 8 has two diametrally-opposite openings 10. In eachopening 10, a tab 11 extends from a portion of the edge of the opening10 opposite from the end portion 7 so that its free end projects intothe corresponding section of the internal channel of the tubular body 6,which internal channel is given overall Reference 13. Each tab 11presents an inside surface 14 sloping relative to the central axis ofthe tubular body 1 so as to form ramps, as explained below.

The internal channel 13 of the tubular body 6 is subdivided axially intotwo sections 13.1 and 13.2. Section 13.1 is situated beside the endportion 7 and possesses a diameter greater than that of the section 13.2which extends beside the end portion 8 and which is connected to thesection 13.1 via a shoulder 13.3.

The internal channel 13 receives a bushing given overall reference 15.

The bushing 15 comprises an annular portion 16 slidably received in thesection 13.1 of the internal channel 13, and it possesses two oppositeends.

One of these ends is provided with an abutment element of flexiblematerial, in this case a sealing gasket given general reference 17 andmade of an elastically-deformable material such as an elastomer. Thesealing gasket 17 comprises a ring 18 of outside diameter that isslightly greater than the diameter of the section 13.1 and of insidediameter that is substantially equal to the inside diameter of the pipeend 1, and a collar 19 having an inside diameter substantially equal tothe outside diameter of the pipe end 1 and an outside diametersubstantially equal to the inside diameter of the above-mentioned end ofthe annular portion 16, the collar 19 being received in said end. Thecollar 19 also presents an internal bead 20 of annular shape and ofdiameter smaller than the outside diameter of the pipe end 1. The insidesurface of the collar 19 is connected to the inside surface of the ring18 via a shoulder 21 formed by a convex frustoconical surface. The ring18 possesses an end face 22 opposite from the collar 19 and of convextapering shape corresponding substantially to the shape of the surface 5of the member 3.

Starting from the end of the annular portion 16 remote from the sealinggasket 17, there are two arms 23 extending axially and each presenting across-section in the form of a circular arc. Each of these arms 23 has afree end 24 which is provided on the inside with means for retaining thepipe end 1. In this case, the retaining means are constituted byrespective metal spikes 25 partially embedded in the free ends 24 so asto project radially inwards. The arms 23 are elastically deformablebetween a rest state in which the spikes 25 define a passage of diameterslightly greater than the outside diameter of the pipe end 1, and adeformed state in which the spikes 25 define a passage of diameterslightly smaller than the outside diameter of the pipe end 1. The freeends 24 have respective outside surfaces 26 presenting respective ramps27 for co-operating with the inside surfaces 14 of the resilient tabs11, and respective steps 28 for coming into abutment against the freeends of the resilient tabs 11.

The bushing 15 is made by injecting two materials;

The bushing 15 is movable between a position in which the retainingmeans are deactivated (see FIG. 3) and a position in which the retainingmeans are actuated (see FIG. 6), as described in greater detail below.

The coupler is properly installed in the member 3 when the end portion 7is anchored in the chamber 4 (FIG. 3).

In a disconnection state, the bushing 15 is in its deactivation position(FIG. 3).

When the pipe end 1 is inserted into the bushing 15, it comes intoabutment with the shoulder 21 and entrains the bushing 15 towards theinternal passage 2. The ramps 27 on the free ends 24 then encounter thesloping surfaces 14 of the tabs 11, thereby deforming the arms 23 fromtheir rest state towards their deformed state (FIGS. 4 and 5).

When the steps 28 goes past the free ends of the tabs 11, the arms 23move apart a little so that the steps 28 face the free ends of the tabs11. The bushing 15 is then in its activation position and the tabs 11constitute abutments against extraction of the bushing 15 from itsactivation position. In addition, the tabs 11 hold the arms 23 in adeformed state in which the spikes 25 bite into the outside surface ofthe pipe end (FIG. 6). At this stage, the ring 18 is compressed betweenthe tapering surface 5 of the member 3 and the end face of the pipe end1, and exerts a reaction force on the bushing 15, holding the steps 28pressed against the free ends of the tabs 11.

Proper connection is indicated by an audible click caused by steps 28coming suddenly into contact with the free ends of the tabs 11. Theappearance of the ends 24 in the openings 10 also informs the operatorthat the connection has been made.

When the circuit in which the coupler is installed is put underpressure, the fluid exerts radial pressure on the sealing gasket 17 viathe inside surface of the ring 18. This pressure is converted into axialforces on the pipe end 1 and on the bushing 15, thereby improvingcontact and thus improving sealing, while subjecting retention of thepipe end to little force, given the small area on which the pressureacts.

Disconnection is achieved by pressing on the free ends 24 of the arms 23through the openings 10 so as to enable the steps 28 to escape from thefree ends of the tabs 11, while simultaneously exerting traction on thepipe end 1. It should be observed that the ability of the pipe end 1 towithstand flattening and the elasticity of the arms 23 act to oppose thethrust applied by the operator on the end 24 during disconnection,thereby further reducing the risk of disconnection taking placeaccidentally. In addition, the need to act simultaneously on both arms23 further limits any risk of accidental disconnection.

The steps 28 then escape from the free ends of the tabs 11, and the pipeend 1 together with the bushing 15 can be moved backwards until theannular portion 16 of the bushing 15 comes into abutment against theshoulder 13.3 between the sections 13.1 and 13.2, which shoulder 13.3defines the deactivation position of the bushing.

In a variant, as shown in FIG. 7, it is possible to cover the endportion 8 in a flexible cap 29 enabling the coupler to be isolated fromthe external environment. This cap 29 is preferably made of anelastically-deformable material so as to make it possible to performdisconnection operations without it being necessary to remove the cap29.

The invention is also applicable to couplers of the union type as usedfor coupling together two pipe ends.

FIG. 8 shows one-half of the coupler, the other half being identicalthereto.

The internal passage 2, the tapering surface 5, and the chamber 4 arethen made directly in the end portion 7 of the tubular body 6, thechamber 4 extending the section 13.1 of the internal channel 13 of thetubular body 6. The bushing 15 is identical to the bushing in theabove-described embodiment.

Naturally, the invention is not limited to the embodiment described, andvariants may be applied-thereto without going beyond the ambit of theinvention as defined by the claims.

In particular, instead of the sealing gasket, the abutment means maycomprise an internal shoulder secured to the bushing downstream from theretaining means relative to the direction in which the pipe end isinserted, and preferably the internal shoulder is made of a flexiblematerial.

In addition, other snap-fastening means can be used, such as a latchmounted on the body to move radially between a locking position in whichthe latch has a portion engaged in a groove in the bushing, and anunlocking position in which said portion is disengaged from the groove.

1. A coupler comprising: a tubular body (6) which is arranged to receivea tubular element for transporting fluid and including a pipe end; abushing (15); retaining means (23, 25) to retain the pipe end of thetubular element, the retaining means being provided along an insidesurface of the bushing; snap means (11) to snap-fasten an outer portionof the bushing, the snap means provided on the tubular body, whichretaining means comprise a tooth for spiking into the pipe end and areselectively activatable and deactivatable, wherein the bushing ismounted in the tubular body to be movable axially between a position foractivating the retaining means and a position for deactivating theretaining means, and wherein the bushing is provided with snap-fasteningmeans complementary to those of the body for co-operating therewith inthe activation position.
 2. A coupler according to claim 1, in which thebushing (15) is provided internally with abutment means (21) againstinsertion of the pipe end into the bushing, and wherein the activationposition of the bushing is downstream from the deactivation positionrelative to the direction in which the pipe end is inserted into thecoupler.
 3. A coupler according to claim 2, in which the abutment meanscomprise an internal shoulder (21) secured to the bushing (15)downstream from the retaining means (23, 25) relative to the pipe endinsertion direction.
 4. A coupler according to claim 3, in which theinternal shoulder (21) is made of a flexible material.
 5. A coupleraccording to claim 4, in which the bushing possesses a downstream endprovided with an elastically-deformable annular gasket (17) having aninternal annular shoulder (21) forming the abutment against insertion ofthe pipe end.
 6. A coupler according to claim 5, wherein the annulargasket (17) possesses an end face (22) remote from the shoulder (21) andarranged to co-operate with a corresponding surface (5) of the body (6).7. A coupler according to claim 6, in which the end face (22) is ofconvex tapering shape.
 8. A coupler according to claim 3, in which theinternal shoulder (21) is of convex tapering shape.
 9. A coupleraccording to claim 1, in which the retaining means comprise at least onearm (23) extending axially and having an end secured to the bushing (15)and a free end (24) provided internally with the tooth (25) for spikinginto the pipe end, the arm being elastically deformable between a firststate in which the spiking tooth is retracted from the bushing and asecond state in which the spiking tooth projects into the bushing.
 10. Acoupler according to claim 9, in which the free end (24) of the arm (23)is arranged to co-operate with an edge of an opening (10) of the tubularbody to hold the bushing (15) in its activation position and to hold thearm (23) in its second state.
 11. A coupler comprising: a tubular body(6) arranged to receive a pipe end of a tubular element for transportingfluid; a bushing (15); retaining means (23, 25) to retain the pipe endof the tubular element, the retaining means being provided along aninside surface of the bushing; snap means (11) to snap-fasten an outerportion of the bushing, the snap means provided on the tubular body; theretaining means being selectively activatable and deactivatable,wherein, the bushing is mounted in the tubular body to be movableaxially between a position for activating the retaining means and aposition for deactivating the retaining means, the bushing is providedwith snap-fastening means complementary to the snap means (11) of thetubular body for co-operating therewith in the activation position, thebushing (15) is provided internally with abutment means (21) againstinsertion of the pipe end into the bushing, and the activation positionof the bushing is downstream from the deactivation position relative tothe direction in which the pipe end is inserted into the coupler.
 12. Acoupler according to claim 11, in which the abutment means comprise aninternal shoulder (21) secured to the bushing (15) downstream from theretaining means (23, 25) relative to the pipe end insertion direction.13. A coupler according to claim 12, in which the internal shoulder (21)is made of a flexible material.
 14. A coupler according to claim 13, inwhich the bushing possesses a downstream end provided with anelastically-deformable annular gasket (17) having an internal annularshoulder (21) forming the abutment against insertion of the pipe end.15. A coupler according to claim 14, wherein the annular gasket (17)possesses an end face (22) remote from the shoulder (21) and arranged toco-operate with a corresponding surface (5) of the body (6).
 16. Acoupler according to claim 15, in which the end face (22) is of convextapering shape.
 17. A coupler according to claim 12, in which theinternal shoulder (21) is of convex tapering shape.
 18. A coupleraccording to claim 11, in which the retaining means comprise at leastone arm (23) extending axially and having an end secured to the bushing(15) and a free end (24) provided internally with a tooth (25) forspiking into the pipe end, the arm being elastically deformable betweena first state in which the spiking tooth is retracted from the bushingand a second state in which the spiking tooth projects into the bushing.19. A coupler according to claim 18, in which the free end (24) of thearm (23) is arranged to co-operate with an edge of an opening (10) ofthe tubular body to hold the bushing (15) in its activation position andto hold the arm (23) in its second state.
 20. A coupler comprising: atubular body (6) arranged to receive a pipe end of a tubular element fortransporting fluid; a bushing (15); a retaining means (23, 25) with atooth for spiking into the pipe end to retain the pipe end of thetubular element, the retaining means provided inside the bushing, theretaining means being selectively activatable and deactivatable; a firstsnap element (11) to snap-fasten an outer portion of the bushing, thefirst snap element provided on the tubular body for co-operatingtherewith in the activation position; and a second snap element providedon the bushing, the second snap element being complementary to the firstsnap element, wherein the bushing is mounted in the tubular body to bemovable axially between a position for activating the retaining meansand a position for deactivating the retaining means.